The invention generally relates to an apparatus and an article for enhancing the coalescence of a dispersed phase from a continuous phase in an emulsion. Particularly, the invention relates to an apparatus and an article for enhancing the coalescence of oil in oil-water emulsions.
Separation of oil from water is one of the key processes in most oil recovery applications. The oil is typically mixed with water, which may be existent in a well or artificially injected to boost the rate of oil recovery. Oil-water separation is also commonly used to reduce the discharged oil fraction to comply with environmental regulations. Sub-sea separators can reduce the power needed to pump produced fluid from the sea bed to the top side, by separating out water from oil prior to pumping.
For sub-sea oil recovery, there may be an economic incentive to make the separation apparatus passive, compact, robust and durable. Further, it may be desirable to operate the sub-sea separator units without external power. Non-limiting example of a suitable sub-sea separator unit is a gravity separator. The driving forces for separation in a gravity separator are oil/water specific gravity difference and the oil/water interface energy. However, the large size of typical gravity separators makes them unsuitable for sub-sea installations. The plate pack separator (PPS) configuration is one of the potential designs for reducing the size of the gravity separators. One of the challenges of plate pack separators is the degradation in separation efficiency over time due to the fouling of corrugated plate surfaces, and resulting loss in surface functionality. In plate pack separators, flat parallel plates are typically used to reduce fouling. However, flat parallel plates have poorer coalescence efficiency compared to corrugated plates.
Accordingly, there is a need for improved oil-water separators. Further, it may be desirable to have oil water separators with improved coalescence efficiency.